TOI

After invisible indexes got introduced in 11g, they have now been enhanced in 12c: You can have multiple indexes on the same set of columns with that feature. Why would you want to use that? Actually, this is always the first question I ask when I see a new feature – sometimes it’s really hard to answer :-)

Here, a plausible use case could be that you expect a new index on the same column to be an improvement over the existing old index, but you are not 100% sure. So instead of just dropping the old index, you make it invisible first to see the outcome:

A small but remarkable change in Oracle Database 12c is the default value of AUDIT_SYS_OPERATIONS has changed to TRUE now. In other words, all actions done by the superuser sys are being audited now by default!

You can now restore single tables from backup! It is a simple command although it leads to much effort by RMAN. See it as an enhancement over a ‘normal’ Point In Time Recovery:

Point In Time Recovery

After a full restore from a sufficiently old backup, archived logs are being applied in direction of the presence until before the logical error. Then a new incarnation comes up (with RESETLOGS) and the whole database is as it was at that time. But what if it is only a dropped table that needs to be recovered? Enter the 12c New Feature:

In 12c, we have introduced online datafile movement as a new feature. Now does that impact an existing standby database? I got asked that yesterday during an online webinar. My answer was that I expect no impact at all on the standby database since redo apply doesn’t care about the physical placement of the datafile on the primary. But I added also that this is just an educated guess because I didn’t test that yet. Now I did: